The field of the invention is serial communication links, and, particularly, local area networks (LANS) in which two or more nodes are connected to a communications media and messages are conveyed between the nodes.
There are numerous protocols employed in local area networks, although many of the protocols have common features and services. One common feature is that when a message is sent from one node to another, a responsive message is promptly sent by the receiving node. For example, a message containing data is sent to a node, and the receiving node promptly acknowledges that the data was, or was not, received accurately. Such messages typically constitute a significant proportion of the traffic on the network, and the efficient handling of such messages can significantly improve the overall efficiency of the entire network.
The speed at which a local area network operates to convey messages between its nodes is determined by a number of factors. The most important factor is the baud rate at which a message is conveyed over the communications media. For example, all other factors being equal, a network which operates at a baud rate of five megabits/second is five times faster than a network which operates at a baud rate of one megabits/second. Another important factor, however, is the efficiency of the network. For example, if considerable time is consumed by the protocol needed to maintain control of the network, or if there is considerable dead time during which no information can be conveyed, the network is less efficient. The present invention addresses the delay, or dead time, between the receipt of a message by a node on the network and that node's transmission of a response.